Simulation Question

A Grader for a certain course with 50 students wanted to
go to a party but had to finish geading a homework with 10 questions
each of which had was marked from 0 to 10 points. Students would get an A
if their total score was greater than 75. The grader wanted to finish
quickly without it being obvious that he had skimped the work. Thus he
decided to simulate the grading and investigated two possibilities
a) Each Question for each student was given a random score between 0 and 10.
b) Each question was given a score based on probability distribution below.
   Mark/Probability
   0	0
   1	.05
   2	.05
   3	.05
   4	.1
   5	.1
   6	.2
   7	.2
   8	.1
   9	.1
   10	.05 adding up to a total probability 1
  
  For each case a) and b), run 10 separate simulations calculating both the mean score
  and the number of students getting an A. If you were the grader and wished to make
  the students happy, would you choose a) or b). Discuss the variability between simulations
  of both the mean and the number of students getting an A.